Monobeam switches



Aug. 22, 1961 K. ROSENBAUM ET AL 2,997,004

MONOBEAM SWITCHES Filed Oct. 23, 19 58 4 Sheets-Sheet 1 BY ya, W

ATTORNEYS Aug. 22, 1961 K. ROSENBAUM ETAL 2,997,004

MONOBEAM SWITCHES Filed Oct. 25, 1958 4 Sheets-Sheet 2 BY P%%%*WATTORNEYS Aug. 22, 1961 K. ROSENBAUM ET AL 2,997,004

MONOBEAM SWITCHES Filed Oct. 25, 1958 4 Sheets-Sheet 3 INVENTORS 62%?6666 0721- 6/6556 A r (910K616? ATTORNEYS g- 1961 K. ROSENBAUM ET AL2,997,004

MONOBEAM SWITCHES 4 Sheets-Sheet 4 Filed Oct. 25, 1958 ATTORNEYS2,997,004 MONOBEAM SWITCHES Kurt Rosenbaum, Essen, Georg Schntze,Koln-Bickendorf, and Engelbert Leyendecker, Koln, Germany, assignors toAlweg-Forschnng G.m.b.H., Koln, Germany, a corporation of Germany FiledOct. 23, 1958, Ser. No. 769,130

Claims priority, application Germany Nov. 2, 1957 9 Claims. (Cl.104-130) The present invention relates to switch constructions and moreparticularly to switch constructions for railway systems of the monobeamtype. In such systems the track comprises a relatively heavy usuallysubstantially rectangular beam member having top and side runningsurfaces, the former supporting the load carrying vehicle wheels and thelatter engaging upper and lower lateral vehicle wheels which guide thevehicle and transfer tilting forces to the beam. Preferably the trackbeam is made of a reinforced concrete structure.

In the past switches for this type of railway have been suggested theswitch tongue of which consists substantially of an elastic beam sectionwhich is bent as a whole from the position connecting a through line toan angularly related branch position. For example, such a switch isdisclosed in copending application Serial No. 751,683, filed July 29,1958. The shape of the switch tongue, when it is deflected, depends onthe location of the point of application of the adjusting force to theswitch tongue. For example, if an elastic switch tongue is fixedlyclamped at one end and the adjusting force acts on the free end, thelongitudinal axis of the switch tongue assumes a parabolic form in itsbranch position, the vertex of the parabola, i.e. the smallest radius ofcurvature, being at the clamping point. From the point of view of theriding dynamics of vehicles passing over the switch, the greatestlateral acceleration occurs at this point abruptly. This is veryunfavorable.

It is the primary purpose and object of the present invention to provideimproved switch construction for monobeam type railways which, withrespect to riding dynamics of vehicles passing the switch, have afavorable bending line in branch position and in which this isaccomplished by simplified, inexpensive structure.

In attaining this primary object and further objects, the inventioncontemplates the provision of a novel switch construction, the bendingline of the switch tongue of which in branch position constitutes twoparabolic branches serving as transition curves having a circular arebetween them located in the middle part of the switch tongue.

In accordance with one form of the invention this can be accomplished bythe provision of a fixed abutment block arranged in such a way that themiddle part of the switch tongue is stopped by it during the bendingprocess and the adjusting force acts at the free end of the switch. Thusthe switch tongue comes into contact with the abutment block before itsfree end is in final branch position and is bent about this block duringthe last phase of operation.

In this case a parabolic bending line is also obtained, the vertex,however, being at the contact point of the switch tongue with theabutment block wherefrom the parabolic branches acting as transitioncurves extend to both ends of the switch tongue, each with continuallyincreasing radius of curvature. For technical and structural reasons anabsolutely rigid clamping of the beam end is very difficult to obtain.Accordingly, the fixed end of the switch tongue may be pivotallysupported by means of a king pin instead of being fixedly clamped.During the first phase of operation of the switch, before the switchtongue contacts the abutment block, it will not be bent but only pivotedabout the king pin, thus an angle is obtained at the king pin during thefirst phase of operation which disappears during the last phase ofoperation.

Since the length of the switch tongue often is limited, the radius ofcurvature at the vertex of the parabolic bending line will become sosmall that a considerable lateral acceleration will be effected on avehicle passing over the switch with high speed.

In order to avoid an unduly short radius of curvature of the circulararc and also to assure sufficient length of the parabolic branchesserving as transition curves, preferably the length of the circular partof the switch tongue should be chosen such that it is not more than norless than of the total length of the elastic switch tongue.

Therefore, according to a further feature of the invention, thecircularly shaped arc of the bending line of the central piece of theswitch tongue can be produced by means of two abutment blocks which arearranged at the ends of the central piece of the switch tongue and aboutwhich the switch tongue is bent in branch position. The bending momentof the switch tongue remains constant between the abutment blocks.Accordingly, the portion of the switch beam between the abutment blocksis bent along a circular arc.

In some cases it is desirable to eliminate the two separate supports forthe abutment blocks. Also, where possible, the use of cantileveredabutment supports on a single pylon should be avoided. The objectivesare achieved by a further embodiment of the invention in which the beamtongue in its center portion and extending along both sides of thecontact point of a single abutment block against which the beam tongueis pressed in branch position, is constructed as a beam of uniformstress with respect to horizontally acting moments.

In such a beam, ie a beam in which the ratio of the section modulus tothe bending moment is constant, the bending line constitutes a circulararc.

Additional objects and advantages will become apparent as thedescription proceeds in connection with the accompanying drawingsillustrating typical embodiments of the invention and in which:

FIGURE 1 is a diagrammatic top plan view of a monobeam switchinstallation with an elastic switch tongue shown in dotted lines innormal position, in dash lines in intermediate position and in fulllines in branch position with its central portion against a singleabutment block;

FIGU RE 2 is a diagrammatic top plan view of a switch having the sameswitch tongue as FIGURE 1, but laterally supported by two abutmentblocks;

FIGURE 3 .is a diagrammatic top plan view of a monobeam switchinstallation, the middle part of the switch tongue being constructed asa beam of uniform stress;

FIGURE 4 is an enlarged cross-section along line 44 of the switch tongueof the embodiment shown in FIG- URE 3;

FIGURE 5 is a partial longitudinal section along line 5-5 of the switchtongue shown in FIGURE 4;

FIGURE 6 is a longitudinal section through the middle part of the switchtongue showing a modification of the embodiment of FIGURE 5;

FIGURE 7 is a top plan view of a modification of the switch according toFIGURE 2, showing the switch in branch position;

FIGURE 8 is a top plan View of a further modification of an elasticmonobeam switch tongue in straight position; and

FIGURE 9 is a top plan view of the switch of FIGURE 8 in branchposition.

Referring now more particularly to the drawings and especially to FIGURE1, the track and switch construction comprises a main line beam 12, asecond main line beam 14 aligned with the beam and a branch line 16.Preferably those beam lines are of substantially rectangularcross-section and are made of reinforced concrete. The ends of the beams12, 14 and 16 and the ends of a switch tongue 18 are mounted on supports20 and 22, the height of which may be chosen according to the specialdemands of the installation. The switch tongue 18 is elasticallydeformable, e.g. made of a light metal alloy construction as disclosedin the copending application Serial No. 751,683 to which reference maybe made for further details.

One end of the beam tongue is pivotally connected to the support 20 bymeans of a king pin construction 24 or the like. Intermediate its endsthe switch tongue 18 is supported for lateral shifting movement along anarcuate support 26.

The switch may be operated by any suitable driving means which per sedoes not form part of this invention and is not shown. For example adriving means similar to that disclosed in United States Patent No.2,903,972 granted September 15, 1959, for Railway Switch Assemblies maybe utilized and may act on the free end of the switch tongue 18.

Interposed between the switch tongue 18 and each of the supports 26 and22 are bogies running on guide rails mounted on the supports 26 and 22,e.g. similar to those shown in the above-mentioned Patent No. 2,903,972and omitted in the drawings of the present case for claritys sake. Inits straight position shown in dotted lines, the switch tongue 18connects the aligned beams 12. and 14. An abutment block 28 limits thestraight position on the elastic switch tongue. During positioning theswitch tongue 18 into the position shown in FIGURE 1, it first assumesthe position shown in dash lines and is then bent about a furtherabutment block 30 mounted on the support 26. At the end of the switchtongue an abutment block 32 limits the movement of the switch tongue endwhen shifted into the branch position. The bending line of the switchtongue in its branch position corresponds to a parabola having itsvertex at the block 30. At this vertex the bending line closelyapproximates a short circular arc.

FIGURE 2 shows a similar switch construction, intermediate of which,however, two supports, 33 and 34, with abutment blocks 35 and 36 arearranged. The bending line obtained by means of this constructionconstitutes two parabolic branches 37 and 38 having between them acircular arc 39 extending between the abutment blocks 35 and 36. Thecircular are 39 obtained has a greater radius of curvature than thatobtained in FIGURE 1 and it insures better properties of riding dynamicsfor vehicles passing over the switch than those passing over a switchaccording to FIGURE 1.

In FIGURE 3 the switch tongue 40 is laterally sup ported by only asingle block 30 as in the embodiment of FIGURE 1. However, in thisdesign the switch tongue 18 within the region 42 is constructed as abeam of uniform stress as shown in greater detail in FIGURES 4 and 5.The bogie structure 43, comprising two angle irons 44 and rolls 46mounted between them, is supported upon the support 26 to facilitatetransverse movement of the elastic switch tongue 40. This switch tonguegenerally is a riveted box-shaped structure comprising normally twoU-shaped girder sheets 48 connected to each other by atop plate 50 and abottom plate 52. Attached to the sides of this box are sheets 54 and 55.Piece 56 serves for stiffening the whole structure. As disclosed in thecopending application Serial No. 751,683, the side running surfaces ofthe structure are formed by blocks 58 made of synthetic plastic, wood orthe like and are screwed or cemented to the side sheets 54 and 55. Bymeans of vertical strengthening sheets 60 and 62 mounted to the sheets48 inside of the box structure, the switch tongue is constructed as abeam of uniform stress in its 4 central part. The strengthening sheetsare diamondshaped as shown in FIGURE 5. Thus the section modulus of thebeam decreases from the center of those sheets longitudinally in bothdirections to the pointed ends 61 and 63 respectively.

Transverse partition walls 64 are arranged in spaced distances from eachother within the switch tongue and are kept in place by means of anglepieces 66, 67 and 68.

FIGURE 6 illustrates another embodiment of the switch tongue which isthe same as the embodiment of FIGURES 4 and 5 except that instead of theabove-mentioned dia mond shaped sheets 60 and 62, triangularstrengthening sheets 70 and 72 are utilized for obtaining a beam ofuniform stress.

In the embodiment of FIGURE 7 the central support 73 is adapted toreceive two stopping blocks 74 and 75, against which the switch tongue76 is pressed in branch position. In straight position the switchcontacts the block 78. Numerals 80 and 82 designate guide rails for thebogies (not shown) interposed between the supports 22 and 73respectively and the switch tongue 76. In branch position the bendingline of this switch tongue is composed of a circular are extendingbetween the blocks 74 and 75 and connecting two parabolic branchesextending between the blocks and the respective adjacent ends of theswitch tongue, said branches serving as transition curves.

FIGURES 8 and 9 show in a more diagrammatic way another modification,FIGURE 8 showing the switch in straight position and FIGURE 9 in branchposition. Within the box shaped switch tongue 18 a rigid member 84 isarranged which has contact pieces 86 and 88 serving as inner abutmentblocks. The rigid member 84 may be of any suitable structure, e.g., arigid frame structure or a strong double-T-girder to which the contactpieces 86 and 88 are welded. The member 84 is centrally supported at andattached to the bottom of the box shaped switch tongue, preferablyswingably by means of a pivot 90. Underneath the member 84 the usualbogie assembly is arranged as indicated by numeral 92 so that lateralforces acting on the member 84 when the switch tongue is in branchposition are transferred over the member 84 on to the bogies 92 to theblock 94 arranged on the support 96. Numeral 98 designates guiding railsfor the bogie assembly 92.

Opposite the contact pieces 86 and 88 identical pieces 100 and 102 arearranged integrally with the rigid mernber 84. The pieces 86, '100 and88, 102 serve as spacers for keeping the correct distance between theside walls of the box-shaped switch tongue and thus between the oppositelateral running surfaces of the switch beam.

In case this switch is used as a three-way switch, i.e. when the switchtongue is adapted to be bent not only to the right as shown in FIGURE 9but also into a left branch position, the contact pieces 100 and 102would act as inner abutment blocks and for this purpose a correspondingabutment block identical to the block 94 would be arranged at the otherside of the switch tongue.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.1

What is claimed and desired to be secured by United States LettersPatent is:

1. A switch assembly for a monobeam track comprising a flexible switchbeam member adapted to connect a first track section selectively withsecond and third angularly related track sections, means pivotallymounting one end of said switch beam member adjacent one end of saidfirst track section, means mounting the opposite end of said switch beammember for shifting movement from a position of alignment with saidsecond track section to a position of alignment with a third tracksection, and abutment means interposed in the path of the centralportion of said switch beam member for arresting the movement of saidcentral portion before the free end of said switch beam member isaligned with said third track section whereby in the continuing movementof said switch beam member it is bent to dispose its longitudinal axison a continuous, smooth curve.

2. The switch assembly according to claim 1 where said smooth curvecomprises a substantially circular central portion in the region of saidabutment means and a pair of substantially parabolic end portions.

3. The combination according to claim 1 wherein said abutment meanscomprises a single block positioned substantially opposite the midpointof said switch beam member.

4. The combination according to claim 1 wherein said abutment meanscomprises a pair of blocks interposed in the path of points spacedsymmetrically about the midpoint of said switch beam member.

5. The combination according to claim 1 wherein said switch beam memberis of hollow construction and said abutment means is carried internallyof said switch beam member in the region of the central portion of saidmember.

6. The combination according to claim 1 wherein said flexible switchbeam member is of hollow construction and has substantially parallel topand bottom walls and substantially parallel side Walls, and additionalstiffening panels rigid with said side walls adjacent the longitudinalmidpoint of said beam, said stifiening panels being of maximum sizeadjacent the midpoint of said beam and being of progressively decreasingsize toward the ends of said beam.

7. A switch assembly for a monobeam track comprising a flexible switchbeam member adapted to connect a first track section selectively withsecond and third angularly related track sections, means pivotallymounting one end of said switch beam member adjacent one end of saidfirst track section, means mounting the opposite end of said switch beammember for shifting movement from a position of alignment with a secondtrack section to a position of alignment with a third track section, and

6 abutment means interposed in the path of the central portion of saidswitch beam member for arresting the movement of said central portion.before the free end of said switch beam member is aligned with saidthird track section whereby in the continuing movement of said switchbeam member it is bent to dispose its longitudinal axis in a continuoussmooth curve having a substantially circular central portion, the lengthof said switch beam member, the position of said abutment means and therelative positions of said first and third track sections being suchthat the length of said circular portion is between one-sixth andtwo-thirds of the total length of said flexible switch beam member.

8. A flexible switch beam member of hollow construction having top,bottom and side walls and additional stifiening panels rigid with eachof said side walls adjacent the longitudinal mid point of said switchbeam member, said stiffening panels being of maximum size adjacent thelongitudinal mid point of said switch beam member and being of uniformlydecreasing size toward the ends of said switch beam member whereby whenone end of said switch beam member is deflected and the mid point ofsaid beam is held against movement, the longitudinal axis of the beamadjacent its longitudinal mid point will be curved on a circular arc.

9. A11 elongated flexible monobeam switch member, said member being ofhollow construction and having top, bottom and side walls, a rigidabutment structure of constant length positioned Within said beamadjacent the longitudinal midpoint thereof, cooperating means on saidabutment structure and said beam for preventing relative longitudinalmovement of said abutment structure with respect to said beam, saidabutment structure having parts adjacent its ends slidably contactingsaid side walls to maintain a predetermined lateral spacing between saidside walls in the region of said parts and said abutment structure beingspaced from said side walls except in the region of said parts to permitthe bending of said Walls when said switch member is flexed along itslongitudinal axis.

References Cited in the file of this patent UNITED STATES PATENTS

